Detergent or cleaning compositions make it possible to clean industrial and domestic hard surfaces. Cleaning compositions generally contain surfactants; solvents, for example alcohol, to possibly facilitate drying; sequestering agents; and bases or acids to adjust the pH. The surfactants are generally nonionic and anionic combinations, or nonionic and cationic combinations. A frequent disadvantage of these cleaning compositions is that the subsequent contact of the hard surface with water leads to the formation of hard water deposits when the surface dries. Moreover, conventional cleaning compositions merely clean the surface, but do little to prevent future soiling.
A solution to this problem was proposed in EP-A-1 196 527, EP-A-1 196 528 and EP-A-1 196 523. These patents propose to deposit on the hard surface a cleaning composition containing a water-soluble amphoteric organic copolymer derived from a cation monomer and an anion or potentially anionic monomer in a sufficient quantity to make the surface absorbent or to improve the hydrophilicity of the surface. This is done to obtain the smallest possible contact angle between the treated surface and a water drop and to ensure the water retention in the vicinity of the treated surface lasts after treatment.
US Patent Application Publication No. 2006/0217286, incorporated herein by reference, discloses compositions for cleaning or rinsing hard surfaces in an aqueous or aqueous/alcoholic medium comprising at least one polybetaine for contributing to the surfaces antideposition and/or antiadhesion properties with regard to soiling substances capable of being deposited on said surfaces.
Many different approaches can be used to change the surface energy (hydrophilicity/hydrophobicity) and thus the adhesion properties of a given material. For example chemical treatments like plasma or ozone for polyethylene and polypropylene surfaces to increase hydrophilicity. Or physico-chemical treatments like the adhesion of surfactant molecules onto hydrophobic surfaces can alter them hydrophilic. Also the adhesion of polymers onto surfaces is used to change surface properties. One specific example would be the adsorption of polyethylene oxide (PEG). In all cases specific chemical groups are attached to the initial surface. These chemical groups change the surface energy and thus the adhesion properties and/or other surface properties like tendency of fouling or slip.
Two of the main disadvantages of the above mentioned treatments are poor durability and/or they are expensive/technically sophisticated. One example of the former is surfactants. They get easily washed away from the surface upon rinsing with e.g. water. An example for the latter is plasma or ozone treatment. Further, for some applications no satisfying solution is found up to date.
Materials that have a low surface energy, such as, for example, polyolefin polymers, have hydrophobic surfaces. The hydrophobic properties of such materials are not desirable in some applications and methods for hydrophilizing low surface energy substrates, including treatment with surfactants and/or high energy treatment, are known. Each of these methods has significant limitations. Surfactant treatments tend to wash off when a treated substrate is exposed to water and the charges imparted to the surface of a treated substrate by high energy treatment tend, particularly in the case of a thermoplastic polymer substrate, to dissipate. The hydrophilic properties of such surfactant treated substrates and high energy treated substrates thus tend to exhibit limited durability. Furthermore, the surfactants that are rinsed off of a treated substrate by exposure to water alter the properties of the water, such as lowering the surface tension, which may also be undesirable.
It would be advantageous to provide a cleaning composition for hard surfaces which imparts improved anti-deposition and/or anti-adhesion properties to a hard surface, particularly anti-soil deposition and anti-soil adhesion properties. It would also be advantageous to provide a cleaning composition for hard surfaces which prevents or minimizes hard water deposits, soap scum, and other mineral deposits. Accordingly, there is a need for more durably hydrophilizing low surface energy hard substrates.